Sanding machine



April 15 1924.

1,490,200 I E. F. BUTTS SANDING MACHINE Filed Aug. 10 1,922 I 2 Sheets-Sheet 1 INVENTOR ATTORNEY April 15 ,1924. 1,490,200

E, F. BUTTS SANDING MACHINE Filed g- 10 1922 2 Sheets-Sheet INVENTOR [/m/ 51/15 6 BY Patented Apr. 15, 19324.

EMIL F. BUTTS, F TACOMA, WASHINGTON, ASSIGNOR OF ONE-HALF TO EDWIN GREGORY, O1? TACOMA, WASHINGTON.

SANDING MACHINE.

Application filed August 10, 1922. Serial No. 581,007.

To all whom it may concern.

Be it known that I, EMIL F. Burrs, a citizen of the United States, residing at Tacoma, in the county of Pierce, State of Washington, have invented certain new and useful Improvements in Sanding Machines, of which the following is a specification.

This invention relates to machines, used in the manufacture of furniture, and kindred industries, for the purpose of smoothing the surface of wood afterit has passed through the machines whereby it is brought t shape and size, and has special reference to a machine for smoothing the curved or molded edges of boards.

The objects of the invention are to provide a machine which will be continuous and uniform in action; which will smooth any curved edge within the limits of the machine; and which is easy t operate and very effective in use.

I attain these and other objects by the devices, mechanisms and arrangements illustrated in the accompanying drawings, in which Fig. 1 is a front elevation of the machine in use; Fig. 2 is a bottom plan of the sanding belt, showing it folded on the idler pulley and unfolded on the drive pulley; Fig. 3 is a perspective view of the pressure block assembly; Fig. 4: is an end elevation thereof, parts being broken away to reveal their construction, and showing the machine sanding the edge of a molded board of the William and Mary design; Fig. 5 is a section showing a part of the steel wearing piece to reveal the action of the saw teeth formed thereon; Fig. 6 is an enlarged end view of a part of the machine to illustrate the folded sand belt engaging the pressure block and the edge of the board being smoothed; and Fig. 7 is a front elevation of the pressure block assembly. Similar numerals of reference refer to similar parts throughout the several views.

The'principle of running a sand belt over a pair of pulleys one of which is driven and actuates the belt, and of pressing the said belt down on the boardto be smoothed by means of a hand manipulated ressure block, is that in common use in san ing ma chines at the present time. 7

Referring to the drawings,-it will be seen in Figs. 1 and 2, that the abrasive belt 1 travels over two pulleys 2 and 3, the'pulley 52 2 being driven by means'not shown, and

driving the belt, and the pulley 3 bein an idler. But, it W111 be seen, that said belt 1, as it passes over the pulley 2, lies flat thereon with its sanded surface against the said pulley, and that as it passes over the idler.

pulley 3 it is folded on itelf, one portion 4: thereof lying with its sanded surface on th said pulley while the folded portion 5 there-- of lies with its sanded surface exposed away from the said pulley. In order to operate a belt in this way it is necessary first to bend or crease the belt 1 in a substantially straight line, as at 6, for the entire length of the belt and parallel to its edges, so that it will always bend on the same line and to the same extent. The belt, being flat on the driver and folded on the. idler, it follows that between the two pulleys the fold.- ing part 5 thereof passes through intermediate positions.

A table 7' is mounted between the two pulleys 2 and 3 and is adapted to support the board 8 whose edge 9 is to be sanded. A bracket or table 10 is supported to the rear of the table 7 and at a slightly lower level. At a point about one-half way between the ends of the table 7, or between the pulleys 2 and 3, I secure the pressure block assembly on'the said bracket 10. The main block 11 thereof is fastened to the bracket 10 by means of two bolts 12, one at each end, whereby it is held down. However, it doesnot touch the said bracket 10 but is held away therefrom by two pairs of thumbscrews 1'3. one pair at each end, and one such screw 13 in front, While the other screw 13 is in the rear, of said bolts 12. The said screws 13 extend entirely through the part of the block 11 inwhich they are screwed and engage against metal bearing plates 14 which are mounted below them on the bracket 10. The purpose of these four screws 13' is to adjust the block 11 slightly. to tip it forward or backward as desired.

A molding-block-carrier 15 is flexibly supported, infront of the main block 11, by means of two pairs of bolts 16 which are secured in the front side of the said main block 11 and extend out horizontally therefrom. These bolts16 pass through vertically elongated slots 17 in said carrier 15,

and have thumb nuts 18 screwing thereon against the metal plate 19, secured to the ends of said carrier 15. Lock nuts 20 are also screwed on 1 1 6 2911 516 to keep the thumb-nuts 18 from being turned by the vibration of the machine. The carrier 15 is held away from the main block 11 by means of the springs 21 mounted in the block 11 around each of the bolts 16 and extending therefrom to a bearing on the rear side of the carrier 15. This resilient support enables the carrier 15 to adjust itself in either a. horizontal or a vertical plane to accommodate slight variations or inaccuracies in the adjustments of the machine and to produce a substantially uniform pressure on the part to be sanded.

The molding block 22 is fixedly, though removably, secured to the front side of the carrier 15, between its ends, and extends in front thereof. This block 22 has a molded or curved part 23, shaped in accordance with the particular design of the edge 9 of the board 8 to be sanded, extending across its front face. One such molding block is therefore provided for each particular form of the edge 9 to be sanded. The portion 4 of the belt 1 rides against the molded part 23, with its cloth back bearing on saidpart, when the edge 9 of the board 8 is pressed thereagainst and forms the pressure block or backing for the said belt. The block 22 has a sharp corner immediately above the mold ed part 23 and a steel piece 24 is inset in the block, said piece having a rounded edge slightly exposed beyond the corner in the block 22, and having sawlike teeth 25 on its inner edge (Fig. 5), said teeth being positioned so as to resist the drag of the traveling belt on the piece 24. The fold or crease 6, in the belt 1, engages this steel piece 24, thus holding said belt into the corner of the molding of the edge 9.

A. belt guide block 26 is fixedly secured to the front side of the molding block 22 and has a portion thereof undercut to receive the metal wearing piece 27 and to form the belt slot 28 between it and the block 22. The folded portion 5, of the belt 1, rides within the slot 28 and its sanded surface is adjacent the wearing piece 27. The belt guide block 26 does not extend down as far as the steel piece 24 but leaves room for the board 8 to pass under it, thus leaving a portion of the part 5 of the belt exposed, to smooth that part of the board edge 9 abovethe said corner therein. 1 v

A pressure lever 29 is mounted at the center of the upper side of themain block 11, being adjustably pressed down thereon'by the thumb-nut 30, on the bolt '31, and being resiliently pressed upward therefrom at its rear end by the spring 32 between it and the main block ,11. Thus its frontendpwhich overhangs the molding block 22" and the guide block 26, presses resiliently, vertically, and adjustably down on thesaid molding block immediately above the'inolded part 23 and the steel corner pi'ece24.

Thus it will be seen that the belt 1, in traveling from the idle pulley 3 to the drive pulley 2, unfolds the part 5 thereof and, near the center of its travel, the said part 5 is substantially vertical and enters the slot 28; that the crease 6 travels along the smooth edge of the steel piece 24; and that the main part 4 of the belt is pressed downward by the molding part 23 of the block 22. Also, it will be seen that, as soon as the edge 9 of a board 8 is pressed towards the block 22, it presses the said part 4 of the belt against the molded part 23 so that the belt then is shaped (longitudinally) in accordance with the particular molding being smoothed thereby; also, that the block 22 will give way somewhat to the side and vertical pressure of the board 8 under the action of the springs 21 and 32 whereby a uniform pressure is assured on the entire molded area adjacent the pressure block. The board 8 is moved along the table 7 and is pressed sideways against the abrasive surface of the belt 1, backed by the resilient pressure block, whereby its molded edge is smoothed from end to end. In practice I prefer to somewhat smooth the abrasive surface of the part 5 of the belt which travels in the slot 28, by holding a piece of sand pa per thereagainst when the belt is new, thus reducing the wear on the metal lining 27, of the slot 28.

Having described my invention, what I claim is 1. In apparatus of the class described, a driven pulley; an idler pulley; a belt mounted onboth said pulleys and having an abrasive surface, said belt lying flat on said driven pulley and folded on said idler pulley; a table adapted to hold the article whose molded edge is to be smoothed: and a pressure block engaging the back of the belt be tween the idler pulley and the driven pulley, and molded to complement the shape of the edge to be smoothed, to back the belt against the side pressure of the said edge.

' 2. In apparatus as set forth in claim 1,together with resilient means between the pressure block and the table, whereby said block is resiliently supported against the pressure of the edge of the article on said belt.

3. In apparatus of the class described, a. driven pulley; an idler pulley; a belt, having an abrasive surface. and creased along its entire length parallel to its edges, said belt lying flat on the driven pulley and folded on said idler pulley; atable adapted to hold the article whose molded edge is to be smoothed; a fixed main block; a carrier sup ported by said fixed main block; a pressure block secured to said carrier and having a surface molded to complement the shape of the edge of the article to be smoothed; a wearing piece mounted in said pressure block and adapted to engage the crease in the belt and parallel thereto; a belt guide secured to said pressure block and shaped to form a slot between said parts wherein the folded portion of the belt travels; and apressure lever mounted on said main block and engaging the pressure block to press downward thereon.

4. In apparatus as set forth in claim 3, wherein the fixed main block is adjustably mounted whereby it may be tipped forward or backward.

5. In apparatus as set forth in claim 3, wherein the carrier is resiliently supported by the fixed main block whereby said carrier may give way to equalize the pressure on the various parts of the molded edge being smoothed.

6. In apparatus as set forth in claim 3, wherein the fixed main block and the carrier are each independently adjustable relatively to the table and the carrier is resiliently supported by the fixed main block.

7. In apparatus as set forth in claim 8, wherein the pressure block is removably secured to the carrier block.

8. In apparatus as set forth in claim 3, wherein the wearing piece has a serrated edge engaging the pressure block to prevent its longitudinal motion under the action of the traveling belt.

9. In apparatus as set forth in claim 3, wherein the slot between the pressure block and the belt guide block is lined with metal to take the wear of the abrasive surface thereon.

10. In apparatus as set forth in claim 3, wherein the pressure lever is resiliently supported by the main block.

11. In apparatus as set forth in claim 8, wherein the pressure lever is resiliently and 40 adjustably supported by the main block.

Signed at Tacoma, Wash, this 28 day of June, 1922.

- 7 EMIL F. BUTTS. 

